Sintered molded parts have a wide variety of industrial applications such as automobile manufacturing where any number of molded engine and/or transmission parts can be manufactured by a variety of molding and sintering techniques. One of the recognized difficulties involved in the production of sintered molded parts is their production with the highest possible density. A molded part may be pressed or compacted in one or more layers from a sinterable powder by those standard powder metallurgy (P/M) methods known in the art. This molded part, referred to as a green compact, may then be sintered, generally under a protective atmosphere, to obtain a strong and dimensionally accurate molded metal part.
The density of sintered molded parts produced by those methods known in the art depends essentially on the density of the green compact produced in the first compaction step, i.e., the green density (compact density). Therefore, it is desirable to produce green compacts in the compaction step that have a density that is as high as possible. However, the high compaction pressures usually used in the those methods known in the art may result in high wear of the die itself and increased ejection sliding friction of the finished green compact. As a result, higher ejection forces must be applied, thereby correspondingly increasing wear of the die. Furthermore, higher ejection forces increase the risk of undesired localized after-compaction and cracking of the green compact. Therefore, there is a need in the art for a composition that, when compacted, possesses high green strength and green density. Still further, there is a need for a composition that will exhibit lower ejection forces and reduce the risk of undesirable high wear of the die.